Welcome to the forums exsilio!
Now assuming your using the stock fan that comes with the cpu, from what i recall that is the right speed. Intel ships there cpus with heatsinks that use a 80mm fan, and the 80mm fans tend to run at a lower rpm to acheive the same cfm a smaller 60 would.
The only other possibility is that your motherboard is either not feeding the fan the right voltage, or its reading the sensor on the fan wrong.